Only add pdb to isolate when fastbuild!=2.

chrome/browser_tests.isolate

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 {
   'includes': [
     'chrome.isolate',
   ],
   'conditions': [
     ['OS=="linux"', {
       'variables': {
@@ skipping 115 matching lines @@
       'variables': {
         'isolate_dependency_tracked': [
           '../native_client/build/build_nexe.py',
           '<(PRODUCT_DIR)/chrome_elf.dll',
           '<(PRODUCT_DIR)/clearkeycdm.dll',
           '<(PRODUCT_DIR)/clearkeycdmadapter.dll',
           '<(PRODUCT_DIR)/ppapi_tests.dll',
           'tools/build/repack_locales.py',
         ],
         'isolate_dependency_untracked': [
+          '<(PRODUCT_DIR)/plugins/',
+        ],
+      },
+    }],
+    ['OS=="win" and (fastbuild==0 or fastbuild==1)', {
+      'variables': {
+        'isolate_dependency_untracked': [
           '<(PRODUCT_DIR)/browser_tests.exe.pdb',
-          '<(PRODUCT_DIR)/plugins/',
         ],
       },
     }],
     ['OS=="win" and libpeer_target_type=="loadable_module"', {
       'variables': {
         'isolate_dependency_tracked': [
           '<(PRODUCT_DIR)/libpeerconnection.dll',
         ],
       },
     }],
@@ skipping 12 matching lines @@
           '../ui/file_manager/file_manager/',
           '../ui/webui/resources/js/',
           '<(PRODUCT_DIR)/chromevox_test_data/',
           '<(PRODUCT_DIR)/locales/',
           '<(PRODUCT_DIR)/resources/chromeos/',
         ],
       },
     }],
   ],
 }